Cartridge for membrane humidifier and membrane humidifier for fuel cell including same

Abstract

The present invention relates to a membrane humidifier cartridge capable of preventing a hollow fiber membrane contained in the cartridge from being damaged by a fluid, and a membrane humidifier for a fuel cell including the same. The membrane humidifier cartridge includes an inner case containing a hollow fiber membrane through which a first fluid flows and formed of a material having a first hardness, a potting part for fixing an end of the hollow fiber membrane, a first mesh hole part including a plurality of windows into which a second fluid flows, and a second mesh hole part including a plurality of windows into which the second fluid flowed in through the first mesh hole part exchanges moisture with the first fluid through the hollow fiber membrane and is then discharged, and at least one of the first mesh hole part and the second mesh hole part includes a shock absorbing part formed of a material having a second hardness lower than the first hardness.

Description

[Technical Field]

[0001] The present invention relates to a cartridge for a membrane humidifier and a membrane humidifier for a fuel cell including the same, and more specifically to a cartridge for a membrane humidifier that can prevent a hollow fiber membrane contained in the cartridge from being damaged by a fluid, and a membrane humidifier for a fuel cell including the same. [Background technology]

[0002] A fuel cell is a power generating battery that generates electricity by combining hydrogen and oxygen. Unlike conventional chemical batteries such as dry batteries and storage batteries, a fuel cell can continuously generate electricity as long as hydrogen and oxygen are supplied, has the advantage of not losing heat, and is twice as efficient as an internal combustion engine. In addition, because the chemical energy generated by the combination of hydrogen and oxygen is directly converted into electrical energy, fuel cells emit fewer pollutants. Therefore, fuel cells are not only environmentally friendly, but also have the advantage of reducing concerns about resource depletion due to increased energy consumption. Such fuel cells can be broadly classified into polymer electrolyte membrane fuel cells (PEMFCs), phosphoric acid fuel cells (PAFCs), molten carbonate fuel cells (MCFCs), solid oxide fuel cells (SOFCs), alkaline fuel cells (AFCs), and the like, depending on the type of electrolyte used. Although each of these fuel cells operates on the same fundamental principle, they differ in the type of fuel used, operating temperature, catalyst, electrolyte, etc. Among them, polymer electrolyte membrane fuel cells (PEMFCs) are known to be the most promising for use in small-scale stationary power generation equipment as well as transportation systems, as they operate at lower temperatures than other fuel cells, have high power density, and can be miniaturized.

[0003] One of the most important factors in improving the performance of polymer electrolyte fuel cells (PEMFCs) is to maintain their efficiency by supplying a certain amount of moisture to the polymer electrolyte membrane (PEM or proton exchange membrane) of the membrane electrode assembly (MEA). If the PEM dries out, the power generation efficiency drops sharply. There are several methods for humidifying a polymer electrolyte membrane, including 1) a bubbler humidification method in which a pressure-resistant container is filled with water and the target gas is passed through a diffuser to supply moisture, 2) a direct injection method in which the amount of moisture required for the fuel cell reaction is calculated and moisture is supplied directly to the gas flow pipe via a solenoid valve, and 3) a humidification membrane method in which moisture is supplied to the gas flow bed using a polymer separation membrane. Among these, the membrane humidification method, which utilizes a membrane that selectively allows only water vapor contained in exhaust gas to pass through and provides water vapor to air supplied to the polymer electrolyte membrane to humidify the polymer electrolyte membrane, is advantageous in that it allows the membrane humidifier to be made lighter and smaller. The selectively permeable membrane used in the membrane humidification method is preferably a hollow fiber membrane, which has a large permeation area per unit volume when forming a module. That is, when a membrane humidifier is manufactured using such a hollow fiber membrane, it is possible to highly integrate hollow fiber membranes with a large contact surface area, and it has the advantages of being able to sufficiently humidify the fuel cell even with a small capacity, being able to use low-cost materials, and being able to recover moisture and heat contained in the off-gas discharged at high temperature from the fuel cell and reuse it through the membrane humidifier. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a cartridge for a membrane humidifier that can prevent a hollow fiber membrane housed in the cartridge from being damaged by a fluid, and a membrane humidifier for a fuel cell that includes the cartridge. [Means for solving the problem]

[0005] A cartridge for a membrane humidifier according to an embodiment of the present invention comprises: The device includes an inner case that houses hollow fiber membranes through which a first fluid flows and is made of a material having a first hardness, a potting portion that fixes ends of the hollow fiber membranes, a first mesh hole portion that includes a plurality of windows into which a second fluid flows, and a second mesh hole portion that includes a plurality of windows through which the second fluid that flows in through the first mesh hole portion exchanges moisture with the first fluid through the hollow fiber membranes and is then discharged. At least one of the first mesh hole portion and the second mesh hole portion includes a shock absorbing portion that is made of a material having a second hardness that is lower than the first hardness. In the cartridge for a membrane humidifier according to an embodiment of the present invention, the shock absorbing part is formed on the side of the hollow fiber membrane of a window frame formed by cutting a part of the inner case, and includes an absorbing layer formed of a material having the second hardness. In the cartridge for a membrane humidifier according to an embodiment of the present invention, the shock absorbing part is formed to surround a window frame formed by cutting a part of the inner case, and also includes an absorbing layer formed of a material having the second hardness. In the cartridge for a membrane humidifier according to an embodiment of the present invention, an opening is formed in the inner case, the first mesh hole portion and the second mesh hole portion are formed in the shock absorbing portion, and the shock absorbing portion covers the opening formed in the inner case and is also an absorption plate made of a material having the second hardness. In the cartridge for a membrane humidifier according to an embodiment of the present invention, the first hardness is in the range of Shore D20-80, and the second hardness is in the range of Shore A5-80.

[0006] A membrane humidifier for a fuel cell according to an embodiment of the present invention comprises: The device includes a midcase for performing moisture exchange between a first fluid and a second fluid, a second fluid inlet for introducing the second fluid into the midcase, a second fluid outlet for discharging the second fluid to the outside, and at least one cartridge disposed within the midcase and containing a plurality of hollow fiber membranes. The cartridge includes an inner case made of a material having a first hardness and containing hollow fiber membranes through which the first fluid flows, a potting portion for fixing ends of the hollow fiber membranes, a first mesh hole portion having a plurality of windows through which the second fluid flows, and a second mesh hole portion having a plurality of windows through which the second fluid flowing through the first mesh hole portion passes through the hollow fiber membranes and then is discharged. At least one of the first mesh hole portion and the second mesh hole portion includes a shock absorbing portion made of a material having a second hardness lower than the first hardness. In the membrane humidifier for a fuel cell according to an embodiment of the present invention, the shock absorbing part is formed on the side of the hollow fiber membrane of a window frame formed by cutting a part of the inner case, and includes an absorbing layer formed of a material having the second hardness. In the membrane humidifier for a fuel cell according to an embodiment of the present invention, the shock absorbing part is formed to surround a window frame formed by cutting a portion of the inner case, and also includes an absorbing layer formed of a material having the second hardness. In the membrane humidifier for a fuel cell according to an embodiment of the present invention, an opening is formed in the inner case, and the first mesh hole portion and the second mesh hole portion are formed in the shock absorbing portion, which covers the opening formed in the inner case and is also an absorption plate formed of a material having the second hardness. In the membrane humidifier for a fuel cell according to an embodiment of the present invention, the first hardness is in a range of Shore D20-80, and the second hardness is in a range of Shore A5-80. Further details of embodiments according to various aspects of the present invention are included in the following detailed description. [Effects of the Invention]

[0007] According to an embodiment of the present invention, the hollow fiber membrane oscillating in the fluid flow direction comes into contact with the shock absorbing portion made of a soft material, thereby reducing friction generated in the hollow fiber membrane and reducing damage caused by repeated use over a long period of time. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a front view illustrating a membrane humidifier for a fuel cell according to one embodiment of the present invention; [Figure 2] 1 is a plan view illustrating a membrane humidifier for a fuel cell according to one embodiment of the present invention; [Figure 3] FIG. 3 is a cross-sectional view taken along line AA' in FIG. 2. [Figure 4] 2 is a plan view illustrating an embodiment of a cartridge installed in a membrane humidifier of a fuel cell, according to an embodiment of the present invention; FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along the line BB′ in FIG. 4. [Figure 6] FIG. 5 is a cross-sectional view taken along the line CC' in FIG. [Figure 7] 10 is a perspective view illustrating another embodiment of a cartridge to be installed in a membrane humidifier of a fuel cell according to an embodiment of the present invention; FIG. [Figure 8] FIG. 8 is a plan view illustrating the cartridge of FIG. 7. [Figure 9] FIG. 9 is a cross-sectional view taken along the line DD' in FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0009] Although the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated and described in detail in the detailed description, but it should be understood that they do not limit the present invention to the specific embodiments, but include all modifications, equivalents, or alternatives that fall within the spirit and technical scope of the present invention. The terms used in the present invention are merely used to describe specific embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly dictates otherwise. In the present invention, terms such as "comprise" or "have" specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and should be understood not to preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. Hereinafter, a membrane humidifier cartridge and a membrane humidifier for a fuel cell including the same according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view illustrating a membrane humidifier for a fuel cell according to one embodiment of the present invention, FIG. 2 is a plan view illustrating a membrane humidifier for a fuel cell according to one embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along line A-A' in FIG. 2. As shown in FIGS. 1-3, a membrane humidifier for a fuel cell according to one embodiment of the present invention includes a humidification module 110 and a cap 120. As shown in FIG. The humidification module 110 exchanges moisture between a first fluid supplied from the outside and a second fluid discharged from a fuel cell stack (not shown). Caps 120 are fastened to both ends of the humidification module 110. One of the caps 120 is formed with a first fluid inlet 121 for supplying the first fluid supplied from the outside to the humidification module 110, and the other is formed with a first fluid outlet 122 for supplying the first fluid humidified by the humidification module 110 to the fuel cell stack.

[0010] The humidification module 110 includes a mid-case 111 having a second fluid inlet 112 and a second fluid outlet 113, and at least one cartridge 20 disposed within the mid-case 111. A second fluid discharged from a fuel cell stack (not shown) flows into the second fluid inlet 112, undergoes moisture exchange within the humidification module 110, and is then discharged through the second fluid outlet 113. In this specification, the fluid flowing in / out of the second fluid inlet 112 or the second fluid outlet 113 is not limited to the second fluid. Furthermore, the fluid flowing in / out of the first fluid inlet 121 or the first fluid outlet 122 is not limited to the first fluid. Depending on the design, one of the caps 120 can supply the second fluid to the humidification module 110 and cause it to flow inside the hollow fiber membrane, while the other can discharge the second fluid after moisture exchange to the outside. In this case, the first fluid flows in through either the second fluid inlet 112 or the second fluid outlet 113, and the first fluid humidified by the humidification module 110 is supplied to the fuel cell stack through the other. The flow directions of the first fluid and the second fluid may be the same or opposite to each other. The midcase 111 and the cap 120 may each be independently formed of hard plastic or metal and have a circular or polygonal widthwise cross section. The circle includes an oval, and the polygon includes a polygon with rounded corners. For example, the hard plastic may be polycarbonate, polyamide (PA), polyphthalamide (PPA), polypropylene (PP), etc. The internal space of the midcase 111 is also divided into a first space S1 and a second space S2 by a partition wall 114. Figure 4 is a plan view illustrating one embodiment of a cartridge to be installed in a membrane humidifier of a fuel cell according to one embodiment of the present invention, Figure 5 is a cross-sectional view taken along line B-B' in Figure 4, and Figure 6 is a cross-sectional view taken along line C-C' in Figure 4. 4 to 6, a cartridge 20 for a membrane humidifier according to one embodiment of the present invention includes a plurality of hollow fiber membranes 21, a potting portion 22, an inner case 23, and a shock absorbing portion 25.

[0011] The hollow fiber membrane 21 also includes a polymer membrane formed from polysulfone resin, polyethersulfone resin, sulfonated polysulfone resin, polyvinylidene fluoride (PVDF) resin, polyacrylonitrile (PAN) resin, polyimide resin, polyamideimide resin, polyesterimide resin, or a mixture of at least two or more of them. The potting portion 22 fixes the end of the hollow fiber membrane 21. The potting portion 22 can also be formed by hardening a liquid resin such as a liquid polyurethane resin through a casting method such as dip potting or centrifugal potting. The inner case 23 has openings at each end and accommodates a number of hollow fiber membranes 21 inside. Potting portions 22, where the ends of the hollow fiber membranes 21 are potted, close the openings of the inner case 23. The inner case 23 has first mesh holes MH1 arranged in a mesh shape for fluid communication with the first space S1, and second mesh holes MH2 arranged in a mesh shape for fluid communication with the second space S2. The second fluid that flows into the first space S1 of the midcase 111 through the second fluid inlet 112 flows into the inner case 23 through the first mesh hole portion MH1, which has a plurality of windows W formed therein, and comes into contact with the outer surface of the hollow fiber membrane 21. Subsequently, the second fluid that has exchanged moisture with the first fluid flows into the second space S2 through the second mesh hole portion MH2, which has a plurality of windows W formed therein, and is then discharged from the midcase 111 through the second fluid outlet 113. If the flow direction of the second fluid is opposite to the flow direction of the first fluid flowing into the first fluid inlet 121, the second fluid that flows into the second space S2 of the midcase 111 through the second fluid outlet 113 flows into the inner case 23 through the second mesh hole portion MH2 and comes into contact with the outer surface of the hollow fiber membrane 21. Subsequently, the second fluid that has exchanged moisture with the first fluid flows through the first mesh hole portion MH1 into the first space S1 and is then discharged from the midcase 111 through the second fluid inlet 112. Such inner case 23 is made of a material having a first hardness to protect the hollow fiber membranes 21 from the pressure of the second fluid. For example, the first hardness is in the range of Shore D 20 to 80. Specifically, the inner case 23 is made of a hard plastic material.

[0012] In a conventional membrane humidifier cartridge, the hollow fiber membrane 21 housed inside the inner case 23 oscillates in the direction of fluid flow due to the second fluid flowing into the inner case 23 through the first mesh hole MH1. As the hollow fiber membrane 21 oscillates, it repeatedly comes into contact with the window frame 24 that forms the window W, causing damage (scratches, breaks, etc.) due to friction. This also occurs when the second fluid is discharged to the outside through the second mesh hole MH2. In order to prevent such damage to the hollow fiber membrane 21, the present invention includes a shock absorbing portion 25. The shock absorbing parts 25 are formed of a material having a second hardness lower than the hardness of the inner case 23. For example, the second hardness may be in the range of Shore A5 to 80. More specifically, the shock absorbing parts 25 may be formed of a soft rubber material such as urethane or silicone. The shock absorbing part 25 may also be formed by a double injection method in the window frame 24 formed by cutting a part of the inner case 23. The window W may also be an internal space formed by, for example, four window frames 24. Here, the shape of the window W is not limited thereto, and may be formed in various shapes such as a polygon, a circle, or an ellipse. 4 to 6, the shock absorbing portion 25 is also formed by an absorbing layer made of a material having a second hardness. The absorbing layer is formed by a double injection method so as to surround the window frame 24. Alternatively, the absorbing layer may be formed only on the hollow fiber membrane side of the window frame 24. The hollow fiber membrane 21, which is oscillated by the second fluid, comes into contact with the shock absorbing part 25, but since the shock absorbing part 25 is made of a soft material, it is possible to reduce friction between the hollow fiber membrane 21 and the shock absorbing part 25. Therefore, even if the hollow fiber membrane 21 is repeatedly contacted during long-term use, damage due to friction (scratches, breaks (single wire), etc.) can be reduced.

[0013] Next, another embodiment of a cartridge for a membrane humidifier will be described with reference to Figures 7 to 9. Figure 7 is a perspective view illustrating another embodiment of a cartridge to be installed in a membrane humidifier of a fuel cell according to an embodiment of the present invention, Figure 8 is a plan view illustrating the cartridge of Figure 7, and Figure 9 is a cross-sectional view taken along line DD' of Figure 8. 7 to 9, a cartridge 20 for a membrane humidifier according to another embodiment of the present invention includes a plurality of hollow fiber membranes 21, a potting portion 22, an inner case 23, and a shock absorbing portion 26. The hollow fiber membrane 21 and the potting portion 22 are substantially the same as those in the above-described embodiment, and therefore will not be described again. In this embodiment, an opening 23a is formed in the inner case 23 instead of the window frame 24, and the shock absorbing part 26 is formed in the form of an absorbing plate that is inserted into the opening 23a and covers the opening 23a. The shock absorbing part 26 is made of a material having a second hardness that is lower than the hardness (first hardness) of the inner case 23. For example, the shock absorbing part 26 may be made of a soft rubber material such as urethane or silicone. In addition, a plurality of windows W for outlets for the second fluid are formed in the shock absorbing part 26, and the plurality of windows W form the mesh hole parts MH1 and MH2. That is, in this embodiment, the shock absorbing part 26 can reduce friction with the hollow fiber membrane 21 while performing the functions of the mesh hole parts MH1 and MH2. The hollow fiber membrane 21, which is oscillated by the second fluid flowing in through the window W formed in the shock absorbing part 26, comes into contact with the shock absorbing part 26, but since the shock absorbing part 26 is made of a soft material, it is possible to reduce friction between the hollow fiber membrane 21 and the shock absorbing part 26. Therefore, even if the hollow fiber membrane 21 is repeatedly contacted during long-term use, damage due to friction (scratches, breaks, etc.) can be reduced.

[0014] Although the above describes the embodiments of the present invention, a person having ordinary knowledge in the art can modify and change the present invention in various ways by adding, changing, deleting or adding components within the scope of the concept of the present invention as set forth in the claims, and these modifications and changes are also within the scope of the present invention.

Claims

1. an inner case that houses a hollow fiber membrane through which a first fluid flows and is made of a material having a first hardness; a potting portion for fixing an end of the hollow fiber membrane; a first mesh hole portion into which a second fluid is introduced and which includes a plurality of windows; a second mesh hole portion including a plurality of windows through which the second fluid introduced through the first mesh hole portion is discharged after exchanging moisture with the first fluid through the hollow fiber membrane, At least one of the first mesh hole portion and the second mesh hole portion includes a shock absorbing portion formed of a material having a second hardness lower than the first hardness, A cartridge for a membrane humidifier, wherein the first mesh hole portion and the second mesh hole portion are formed in the inner case or the shock absorbing portion attached to the inner case.

2. The shock absorbing portion is 2. The cartridge for a membrane humidifier according to claim 1, further comprising an absorbent layer formed on a surface facing the hollow fiber membrane in a window frame formed by cutting out a portion of the inner case, the absorbent layer being made of a material having the second hardness.

3. The shock absorbing portion is a window frame formed by cutting a portion of the inner case; 2. The cartridge for a membrane humidifier according to claim 1, further comprising: an absorbent layer formed to surround the window frame and made of a material having the second hardness.

4. An opening is formed in the inner case, the first mesh hole portion and the second mesh hole portion are formed in the shock absorbing portion, 2. The cartridge for a membrane humidifier according to claim 1, wherein the shock absorbing part is an absorption plate that covers an opening formed in the inner case and is made of a material having the second hardness.

5. 5. The cartridge for a membrane humidifier according to claim 1, wherein the first hardness is in a range of Shore D20 to 80, and the second hardness is in a range of Shore A5 to 80.

6. performing moisture exchange between the first fluid and the second fluid; Mid case and a second fluid inlet for allowing the second fluid to flow into the midcase; a second fluid outlet for discharging the second fluid to the outside; At least one cartridge disposed in the midcase and containing a plurality of hollow fiber membranes; The cartridge comprises: an inner case that houses a hollow fiber membrane through which a first fluid flows and is made of a material having a first hardness; a potting portion for fixing an end of the hollow fiber membrane; a first mesh hole portion into which a second fluid is introduced and which includes a plurality of windows; a second mesh hole portion including a plurality of windows through which the second fluid introduced through the first mesh hole portion is discharged after exchanging moisture with the first fluid through the hollow fiber membrane, At least one of the first mesh hole portion and the second mesh hole portion is a shock absorbing portion formed of a material having a second hardness lower than the first hardness, A membrane humidifier for a fuel cell, wherein the first mesh hole portion and the second mesh hole portion are formed in the inner case or the shock absorbing portion attached to the inner case.

7. The shock absorbing portion is 7. The membrane humidifier for a fuel cell according to claim 6, further comprising an absorption layer formed on a surface facing the hollow fiber membrane in a window frame formed by cutting out a portion of the inner case, the absorption layer being made of a material having the second hardness.

8. The shock absorbing portion is a window frame formed by cutting a portion of the inner case; 7. The membrane humidifier for a fuel cell according to claim 6, further comprising: an absorption layer formed to surround the window frame and made of the material having the second hardness.

9. The shock absorbing portion is An opening is formed in the inner case, the first mesh hole portion and the second mesh hole portion are formed in the shock absorbing portion, 7. The membrane humidifier for a fuel cell according to claim 6, wherein the shock absorbing part is an absorption plate that covers an opening formed in the inner case and is made of a material having the second hardness.

10. 10. The membrane humidifier of claim 6, wherein the first hardness is in a range of Shore D20 to 80, and the second hardness is in a range of Shore A5 to 80.

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